Beyond the bugs, I don't think those roots are too shabby for a short-lived auto. They look mostly healthy and evenly spread throughout. But something was living down there . I've never seen anything alive in my rootballs (knock wood!).
In terms of air pruning, it causes the plant to send out new roots from the main center roots, which creates new feeder roots (the small ones charged with taking up nutrients and water). When plants get root bound in plastic pots, the main roots keep getting bigger and wrap around the outside of the substrate but don't produce new feeder roots, which lowers the plant's ability to take up what it needs to survive.
As I recall... .
I've had completely root bound plants in cloth pots, and other than needing water every. damn. day, they didn't suffer deficiencies. They would have looked totally different had they been in plastic.